Communication cables employing optical fibers are widely used in the telecommunications industry. In particular, multifiber cables are widely used for long distance telephone communications, interexchange telephone applications, and other telephony and data transmission applications. Fiber optic cables are also being incorporated into cable television networks in place of more traditional coaxial cables. Optical fibers may permit long distances between signal repeaters or eliminate the need for such repeaters altogether. In addition, optical fibers offer extremely wide bandwidths and low noise operation.
A traditional used embodiment of fiber optic cables in telecom industry are the so called ADSS (All-Dielectric Self Supporting) cables. They typically include one central element surrounded by several fiber protecting tubes named “loose tube”, since the internal diameter of these protective tubes are several times bigger than the diameter of the group of inserted fibers. There is an internal cable sheath placed around the group of loose tubes. Aramid layers are placed between the inner and an outer cable sheath. This aramid layers ensure the necessary tensile strength for the cable to be applicable for aerial implementations.
Another traditional aerial optical cable type, which has been used for trunk and backbone network applications for a long time is the so called “figure 8” type cable, which consists of a central element, surrounded by fiber protecting loose tubes. Around the loose tubes is a single cable sheath placed. This cable sheath is extruded together with a support element forming a single physical unit. The support element wire can be steel wire, rope or made from dielectric material like FRP (Fiber Reinforced Plastic). This support element wire (rope) ensures the necessary tensile strength for the cable and makes it applicable for aerial networks.
A common problem of all cable types is the high effort for their installation, which rises with the number of access closures.